This release fixes a serious vulnerability in the Wi-Fi chips used in iPhone, iPad, and iPod touch, which allows an attacker to remotely take control of your device over a wireless network.

Like a lot of mobile devices, Apple’s use Broadcom chips for Wi-Fi connectivity. But it turns out that the BCM43xx family of chips, which is used in iPhone 5 to iPhone 7, the fourth-generation iPad and later, and the latest iPod touch, contains a serious vulnerability.

Dubbed “Broadpwn,” it allows an attacker to take control of your device while it is searching for a Wi-Fi network — even without your passcode or Apple ID. Your device simply needs to be within wireless range of the hacker, who can crash your phone or tablet remotely.

Apple wasn’t the only company affected by this; lots of others use Broadcom chips, too. Google rolled out an Android update to address the problem earlier this month, and now Apple has caught up with iOS 10.3.3.

The company confirmed in its release notes that a serious security flaw was fixed, but it didn’t mention Broadpwn specifically. Now CNET has confirmed that the exploit has been patched. If you use Wi-Fi (who doesn’t?), then you should update as soon as you can.